Functions of XL2 Analyzer

Besides being an advanced, integrating Sound Level Meter, the XL2 measures RTA and FFT high-resolution spectra, RT60 Reverberation Time, Polarity, Delay and THD+N. Optional features are speech intelligibility STIPA, extended acoustics functions, noise curves, cinema calibration, pass/fail analysis and remote measurement acquisition. The Type Approval Option upgrades the instrument to the XL2-TA, a type approved sound level meter.

Sound Level Meter - The Flexible Solution

The XL2 is a powerful sound level meter for events and environmental noise monitoring. Numerous measurement variations are available. Actual level, Lmin, Lmax and Leq may be measured in combination with frequency weighting A, C or Z and time weightings fast, slow and optional impulse. All results are simultaneously available.

XL2 Sound Level Meter

Customers may log all acquired level information onto a removable SD card. Additionally the XL2 offers wav-file recording for a complete documentation of the measured sound pressure levels. Voice notes may also be added to each measurement.


  • Standards
    • IEC 61672, IEC 60651, IEC 60804, IEC 61260
    • China: GB/T 3785:2010, GB/T 3241, GB 3096-2008, GB 50526, GB-T_4959-1995
    • Germany: DIN 15905-5, DIN 45645-2, optional: DIN 45645-1
    • Japan: JIS C1509-1:2005, JIS C 1513 class 1, JIS C 1514 class 0
    • Switzerland: SLV
    • UK: BS6698, BS5969
    • US: ANSI S1.4:2014, ANSI S1.43, ANSI S1.11:2014
    • SMPTE ST 202:2010, ISO 2969:2015
  • Sound levels
    • SPL actual, Lmin, Lmax, Lpeak, Leq, gliding Leq
    • Frequency weighting: A, C, Z (=flat) simultaneously
    • Time weighting: Fast, slow and optional impulse simultaneously
    • Correction values k1, k2
    • Indicators show when sound level limits are exceeded
    • Digital I/O interface for the control of external peripherals
    • Sound Exposure Level LAE (optional)
    • Percentile statistics for Lxy (x= A, C or Z, y= F, S or EQ1"): 1 - 99% (optional)
    • Calculated levels: LCeq - LAeq, LAIeq - LAeq, LAFT5eq -LAeq (optional)
    • Clock-impulse maximum level "TaktMax" in accordance with DIN 45645-1 (optional)
  • Logging and Reporting
    • All levels simultaneously
    • Short-time levels including spectrum for 1 second or longer
    • Wav-file for listening (compressed)
    • Data logging in 100 ms intervals (optional)
    • Linear wav-files with 24 bit, 48 kHz resolution (optional)
  • Remote measurement acquisition (optional)

Real Time Analyzer RTA

The RTA perfectly suits tasks such as optimization of sound systems and rooms. The XL2 measures and logs wideband values and the real time spectrum in 1/1 or 1/3 octave-band resolution according to IEC 61260 class 0. The sound level meter results of the wideband and RTA spectrum are simultaneously available.

XL2 Sound Level Meter


  • 1/3 octave, 1/1 octave
  • Frequency weighting: A, C, Z (=flat)
  • Time weighting: Fast, slow and optional impulse
  • Percentile statistics for Lxy (x= A, C or Z, y= F or S ): 1 - 99% (optional)

Acoustic Analyzer

FFT Analysis

XL2 FFT AnalyseThe real-time FFT is the ideal tool for visualization of comb filters and narrow band effects. It measures the actual level and the averaged level Leq in three ranges over the entire audio band. The optional Extended Acoustic Pack offers an additional high-resolution Zoom-FFT up to 0.4 Hz steps in the frequency range 5 Hz - 20 kHz. The Spectral Limits Option extends the FFT Analysis with trace capturing, relative curve display and comprehensive tolerance handling.

RT60 Reverberation Time

XL2 RT60 NachhallzeitmessungThe XL2 measures the energy decay in the range from 63 Hz to 8 kHz by the Schroeder method in 1/1 octave bands. Automatic triggering and averaging of multiple measurements simplifies the operation and minimizes the measurement time. Use either an impulse source or an interrupted pink noise as the test signal. The optional Extended Acoustic Pack extends the RT60 measurement to a 1/3 octave resolution.


XL2 PolaritätFor a stereo sound image, it is important to match the polarities of the left and right speakers. The XL2 measures the polarity of cables, single speakers and speaker cabinets. The detailed result page displays the measured polarity as octave bands from 125 Hz to 8 kHz. This allows in-depth verification of the polarity - frequency relation. The polarity test signal is provided by the NTi Audio Test CD or the Minirator test signal generator.

Delay Time

XL2 LaufzeitThe delay function supports the accurate setup of delay lines and thus the optimization of the directionality of the signal source. The XL2 measures the delay time between the electrical reference signal and the acoustic signal from the speaker. The required delay settings are displayed automatically, allowing the audio engineer to set the measured delay time directly into the delay device in the rack.

Speech Intelligibility STIPA (optional)

XL2 Sprachverständlichkeit STIPAThe XL2 Analyzer measures speech intelligibility according to the latest revision of standard IEC 60268-16:2011 (edition 4) as well as older revisions. It offers ambient noise correction and automated averaging for consecutive measurements. The XL2 displays the measurement results as STI or CIS, accompanied by the individual levels and modulation indices of the seven octave bands.

The measurement results are acquired from the dedicated STIPA test signal source:

  • NTi Audio TalkBox
    Acoustic signal generator, required for audio systems that include voice microphones, allows the entire signal chain to be measured.
  • Minirator MR-PRO
    Test signal generator, required for audio systems with line inputs
  • STIPA Test CD

1/12 Octave Band Analysis (optional)

XL2 Oktavband AnalyseThe Spectral Limits Option extends the function range of the XL2 with a 1/6th and 1/12th octave RTA analyzer. The XL2 Analyzer compares spectral measurements against a tolerance band and shows exceptions in every frequency band. This passed/failed condition is further visualized by the limit button and forwarded to the I/O interface of the instrument in order to drive an external alarm device such the accessory Stack Light.

Noise Curves (optional)

XL2 Noise CurvesThe noise curve measurement provides an objective rating of the background noise level in a room or environment. The noise curve rating of a spectrum is designated as the value of the highest noise curve “touched” by the measured octave-band spectrum. The speech interference level (SIL) and the noise curve rating are calculated in parallel. The Noise Curve function is offered with the Spectral Limits Option.

Supported noise curve measurements and standards:

  • Noise Rating (NR)
    in accordance with ISO 1996
  • Noise Criteria (NC)
    in accordance with ANSI 12.2-2008 and -1995
  • Room Noise Criteria (RNC)
    in accordance with ANSI 12.2-2008
  • Room Criteria (RC)
    in accordance with ANSI 12.2-1995
  • Preferred Noise Criteria (PNC)
    in accordance with ASA 1971

Analog Audio Analyzer

Level RMS / THD+N

XL2 Effektivwertpegel RMS / THD+NThe XL2 with balanced XLR and unbalanced RCA inputs offers a comprehensive, high performance audio analyzer. It simultaneously measures balance, level, distortion (THD+N) and frequency. The internal loudspeaker or headphone output offers audible monitoring of either the input signal or just the residual distortion. The optimized low distortion and low noise design enable level measurements down to -112 dBu and residual distortions typically lower than -100 dB, which is unmatched in handheld instruments.

Audio Spectrum

XL2 Spektrale AudiomessungSpectral audio measurements are offered in the units Volt, dBu and dBV within the following measurement functions:

  • Sound Level Meter (1/3 and 1/1 Octave)
  • FFT
  • 1/12 Octave (optional)


XL2 OszilloskopThe scope function visualizes the waveform of the electrical input signal. It triggers to the fundamental frequency and selects the scaling of the X-axis (time) and Y-axis (level) automatically. The fundamental or most dominant frequency is displayed above the scope screen.

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